A) Field of the Invention
The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device which is suitable for light emission in the wavelength band providing a high reception sensitivity of a photodiode using silicon and is capable of both increasing a light emission output and raising a cutoff frequency.
B) Description of the Related Art
A double-hetero type light emitting diode having a Zn doped GaAs layer sandwiched between AlGaAs layers is known as a device for outputting light in the infrared band (infrared band from a wavelength of 92 nm to a shorter wavelength) providing a high reception sensitivity of a photodiode using silicon. If the Zn concentration of a GaAs layer is increased, the cutoff frequency of a light emitting diode can be raised. However, if the Zn concentration is increased, a light emission output lowers considerably.